Out of three given numbers, the first number is twice the second and thrice the third. If the average of these three numbers is 154, then what is the difference between the first and the third numbers?

Clearly, if A runs 600 meters, B runs = 540 m.
? If A runs 400 m, B runs = 540 x 400 / 600 = 540 x 4 / 6 = 90 x 4 = 360 m
Again, when B runs 500 m, C runs = 450 m
? When B runs 360 m, C runs = 450 x 360 / 500 = 45 x 36 / 5 = 9 x 36 = 324 m.
? A beats C by 400 - 324 = 76 m.

36.98276421 x 21.00002
Using nearest value in whole number for 36.9827421 is 37 and 21.0002 is 21
? 37 x 21 = 777 ? 775

    = Unit digit in [(4²)⁸⁹⁶ x 4]

    = Unit digit in (6 x 4) = 4

Unit digit in (625)³¹⁷ = Unit digit in (5)³¹⁷ = 5

Unit digit in (341)⁴⁹¹ = Unit digit in (1)⁴⁹¹ = 1

Required digit = Unit digit in (4 x 5 x 1) = 0.

(A's speed) : (B's speed) = √b : √a = √16 : √9 = 4 : 3.

Unit digit must be 0 or 5 and sum of digits must be divisible by 9.

Among given numbers, such number is 202860.

Then, x = 7589 - 3434 = 4155

At 11 : 50 A.M. from the formula here P = 11 and Q = 50 so required angle is 11 x 50/2 - 30 x 11 = 275 - 330 = -55 or ignoring the negative sign the required angle is 55°